@Sharma, Ritika Thanks for posting your question in Microsoft Q&A, apologize for any inconvenience caused on this.
1.Blank object received for --> userFacingDiagnostics.network.getLatest()
As per the documentation here, this value will be defined if the event never got fired.
2.Event not triggered when it should.
Ideally, these events get fired off that could indicate due to some underlying issue (poor network, user has their microphone muted) that a user might have a poor experience.